Java Programming - MCQ Practice Questions

For encrypting data while writing to a file, which approach is most appropriate?

In Java NIO, what is a key advantage of FileChannel over traditional I/O streams?

Which serialization approach maintains backward compatibility better?

For developing a high-performance file copying utility handling files up to 10GB, which approach is optimal?

Given the code: PrintWriter pw = new PrintWriter(new FileWriter("file.txt")); What issue might occur?

Which approach would you use to read and write objects to a file efficiently in a production application?

In a log aggregation system, what is the primary advantage of using RandomAccessFile over sequential streams?

What is the main advantage of using RandomAccessFile over sequential streams?

When deserializing an object, which methods are called in order?

Consider a scenario where you need to read a large binary file efficiently without loading it entirely into memory. Which approach combines best practices?

What is the primary advantage of PushbackInputStream?

In a multi-threaded application, multiple threads are writing to the same file simultaneously using FileOutputStream. What is the primary issue and best solution?

Consider code: String query = "SELECT * FROM users WHERE id=" + userId; stmt.executeQuery(query); What security issue exists?

How would you implement batch processing in JDBC for multiple INSERT operations?

What is the difference between execute(), executeQuery(), and executeUpdate()?

Which JDBC feature allows you to call stored procedures?

In JDBC, what does the ResultSet.TYPE_SCROLL_INSENSITIVE constant represent?

What is the difference between update() and updateRow() methods in ResultSet?

A developer wants to prevent SQL injection attacks while executing dynamic queries. Which approach is most secure?

What is the default transaction isolation level in JDBC when autocommit is disabled?